NGC 7538
E109441
NGC 7538 is a massive star-forming nebula in the constellation Cepheus, notable for hosting some of the largest known protostars in the Milky Way.
All labels observed (18)
| Label | Occurrences |
|---|---|
| NGC 7538 canonical | 1 |
| NGC 7538 E | 1 |
| NGC 7538 IRS 1 | 1 |
| NGC 7538 IRS 10 | 1 |
| NGC 7538 IRS 11 | 1 |
| NGC 7538 IRS 12 | 1 |
| NGC 7538 IRS 13 | 1 |
| NGC 7538 IRS 14 | 1 |
| NGC 7538 IRS 2 | 1 |
| NGC 7538 IRS 3 | 1 |
| NGC 7538 IRS 4 | 1 |
| NGC 7538 IRS 5 | 1 |
| NGC 7538 IRS 6 | 1 |
| NGC 7538 IRS 7 | 1 |
| NGC 7538 IRS 8 | 1 |
| NGC 7538 IRS 9 | 1 |
| NGC 7538 N | 1 |
| NGC 7538 S | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T934098 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
NED1
Entity disambiguation (via context triple)
gpt-5-mini-2025-08-07
Target entity: NGC 7538 Context triple: [Perseus Arm, contains, NGC 7538]
-
A.
Messier 17
Messier 17, also known as the Omega or Swan Nebula, is a bright star-forming emission nebula located in the constellation Sagittarius.
-
B.
Eagle Nebula
The Eagle Nebula is a famous star-forming region in the Milky Way best known for the "Pillars of Creation," towering columns of gas and dust captured in iconic Hubble Space Telescope images.
-
C.
NGC 6822
NGC 6822 is a barred irregular dwarf galaxy located in the constellation Sagittarius and is one of the nearest and best-studied galaxies outside the Milky Way.
-
D.
Carina Nebula
The Carina Nebula is a vast, active star-forming region in the Milky Way known for its towering gas and dust pillars and dramatic young stellar clusters.
-
E.
Orion Molecular Cloud Complex
The Orion Molecular Cloud Complex is a vast star-forming region in the constellation Orion, rich in gas, dust, and young stellar objects, and one of the most studied nurseries of massive stars in the Milky Way.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
NED2
Entity disambiguation (via description)
gpt-5-mini-2025-08-07
Target entity: NGC 7538 Target entity description: NGC 7538 is a massive star-forming nebula in the constellation Cepheus, notable for hosting some of the largest known protostars in the Milky Way.
-
A.
Messier 17
Messier 17, also known as the Omega or Swan Nebula, is a bright star-forming emission nebula located in the constellation Sagittarius.
-
B.
Eagle Nebula
The Eagle Nebula is a famous star-forming region in the Milky Way best known for the "Pillars of Creation," towering columns of gas and dust captured in iconic Hubble Space Telescope images.
-
C.
NGC 6822
NGC 6822 is a barred irregular dwarf galaxy located in the constellation Sagittarius and is one of the nearest and best-studied galaxies outside the Milky Way.
-
D.
Carina Nebula
The Carina Nebula is a vast, active star-forming region in the Milky Way known for its towering gas and dust pillars and dramatic young stellar clusters.
-
E.
Orion Molecular Cloud Complex
The Orion Molecular Cloud Complex is a vast star-forming region in the constellation Orion, rich in gas, dust, and young stellar objects, and one of the most studied nurseries of massive stars in the Milky Way.
- F. None of above. chosen
Statements (63)
| Predicate | Object |
|---|---|
| instanceOf |
H II region
ⓘ
emission nebula ⓘ molecular cloud ⓘ star-forming region ⓘ |
| catalog | New General Catalogue ⓘ |
| constellation |
Cassiopeia
ⓘ
surface form:
Cepheus
|
| contains |
NGC 7538
self-linksurface differs
ⓘ
surface form:
NGC 7538 E
NGC 7538 self-linksurface differs ⓘ
surface form:
NGC 7538 IRS 1
NGC 7538 self-linksurface differs ⓘ
surface form:
NGC 7538 IRS 10
NGC 7538 self-linksurface differs ⓘ
surface form:
NGC 7538 IRS 11
NGC 7538 self-linksurface differs ⓘ
surface form:
NGC 7538 IRS 12
NGC 7538 self-linksurface differs ⓘ
surface form:
NGC 7538 IRS 13
NGC 7538 self-linksurface differs ⓘ
surface form:
NGC 7538 IRS 14
NGC 7538 self-linksurface differs ⓘ
surface form:
NGC 7538 IRS 2
NGC 7538 self-linksurface differs ⓘ
surface form:
NGC 7538 IRS 3
NGC 7538 self-linksurface differs ⓘ
surface form:
NGC 7538 IRS 4
NGC 7538 self-linksurface differs ⓘ
surface form:
NGC 7538 IRS 5
NGC 7538 self-linksurface differs ⓘ
surface form:
NGC 7538 IRS 6
NGC 7538 self-linksurface differs ⓘ
surface form:
NGC 7538 IRS 7
NGC 7538 self-linksurface differs ⓘ
surface form:
NGC 7538 IRS 8
NGC 7538 self-linksurface differs ⓘ
surface form:
NGC 7538 IRS 9
NGC 7538 self-linksurface differs ⓘ
surface form:
NGC 7538 N
NGC 7538 self-linksurface differs ⓘ
surface form:
NGC 7538 S
dense molecular cores ⓘ infrared sources ⓘ maser sources ⓘ massive protostars ⓘ ultracompact H II regions ⓘ |
| declination | +61° 30′ ⓘ |
| discoveredBy | William Herschel ⓘ |
| discoveryYear | 1787 ⓘ |
| distanceFromEarth |
approximately 2.8 kiloparsecs
ⓘ
approximately 9100 light-years ⓘ |
| environment |
cold dense molecular gas
ⓘ
strong UV radiation field ⓘ |
| galacticLatitude | +0.78 degrees ⓘ |
| galacticLongitude | 111.54 degrees ⓘ |
| hasFeature |
CO outflows
ⓘ
OH masers ⓘ bipolar molecular outflows ⓘ complex filamentary structure ⓘ dust lanes ⓘ embedded young stellar objects ⓘ methanol masers ⓘ reflection nebula components ⓘ water masers ⓘ |
| hasStarFormation |
clustered star formation
ⓘ
high-mass star formation ⓘ |
| ionizingSource | massive O-type stars ⓘ |
| locatedIn |
Milky Way
ⓘ
Perseus Arm ⓘ |
| notableFor |
hosting some of the largest known protostars in the Milky Way
ⓘ
massive star formation ⓘ |
| observedIn |
infrared wavelengths
ⓘ
radio wavelengths ⓘ submillimeter wavelengths ⓘ |
| partOf | Cepheus OB2 association ⓘ |
| regionType | giant molecular cloud complex ⓘ |
| researchUse |
laboratory for studying maser emission
ⓘ
laboratory for studying massive star formation ⓘ laboratory for studying protostellar evolution ⓘ |
| rightAscension | 23h 13m ⓘ |
| visibleIn | small amateur telescopes under dark skies ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: NGC 7538 Description of subject: NGC 7538 is a massive star-forming nebula in the constellation Cepheus, notable for hosting some of the largest known protostars in the Milky Way.
Referenced by (18)
Full triples — surface form annotated when it differs from this entity's canonical label.